Proteins are composed of a series of amino acid residues. There are 20 naturally occurring amino acid residues. The three-dimensional structure of a protein typically comprises a series of folded regions. When predicting the structure of a protein, researchers attempt to determine the amino acid spatial order and location in three-dimensional space. Obtaining the three-dimensional structure of a protein is important because protein function depends upon the particular protein structure.
Understanding multi-domain protein folding is a current focus in protein science that remains a great challenge for researchers. For example, little, if anything, is known about how domain sequence boundaries are determined, how each individual domain folds (e.g., independently or cooperatively) or how domains assemble after each individual domains is formed. See, for example, R. Jaenicke, Stability and Folding of Domain Proteins, 71 PROG. BIOPHYS. & MOL. BIOL. 155-241 (1999); C. Anselmi, et al., Identification of Protein Domains on Topological Basis, 58 BIOPOLYMERS 218-229 (2001); S. J. Wheelan et al., Domain Size Distributions Can Predict Domain Boundaries, 16 BIOINFORMATICS 613-618 (2000); A. G. Murzin et al., SCOP: A Structural Classification of Protein Database for the Investigation of Sequences and Structures, 247 J. MOL. BIOL. 536-540 (1995), the disclosures of which are incorporated by reference herein.
Therefore, techniques would be desirable that allow for the analysis and elucidation of protein structures, including those having multiple domains.